Shears.



H. M. SWAN.

SHEARS.

APPLIOATION FILED APR.'16, 1910.

989,824. Patented Apr.18,'1911.

rm NORRIS PETERS C0,, wAsul/vcrun, a. C4

HARRY M. swan, or 00mm,

PENNSYLVANIA, ASSIGNOR T0 JOHN C. TH01VIS, AGENT, OF ERIE, PENNSYLVANIA.

SHEARS.

To all whom it may concern:

Be it known that I, HARRY M. SWAN, citizen of the United States, andresiding at Corry, county of Erie, and State of Pennsylvania, haveinvented new and useful Improvements in Shears, of which the followingis a specification.

This invention relates to shears, and consists in certain improvementsin the construction thereof as will be hereinafter fully described andpointed out in the claims.

More particularly the invention relates to that type of shearsordinarily used by tinners. With this type of shears where the thicknessof the metal varies, the thicker plates cannot be inserted between theopen blades as far as desirable.

One of the objects of this invention is 'to obviate this difliculty, andit is accomplished by varying the pivotal mounting of one of the bladesrelatively to the other blade so as to vary the opening of the shears.In this way, the opening in the shears can be carried back to a positionnear the pivot and can be of such extent as to permit the readyinsertion of any plate within the capacity of the shears.

Figure l is a side elevation of the shears, with the blades open; Fig. 2a top view of the shears partly in section; Fig. 3 is a side elevationof the shears with the blades closed; Fig. 4 a section on the line 4'1in llliig. 3; Fig. 5 a section on the line 55 in 1 marks the stationaryblade, and has the usual projection 2 for securing it to the bench; 3the movable blade; 1 and 5 the cutting edges of the blades. The movableblade is pivoted on the pin 6 which is carried by a movable mounting 7,the blade being secured by the nut 8. The movable mounting 7 ispivot-ally secured to the stationary blade 1 by screw 9. A lever arm 10extends upwardly from the mounting by means of which it can be operated.

It will be observed that by swinging the mounting 7 the opening betweenthe edges of the blades may be materially increased. Thus in Fig. 1 theopening extends back to the rear ends of the cuttin edges of the blades.The cutting edge ot the stationary blade is shown in Fig. 3 in dottedlines, and in this figure, the movable mounting has been swung from theposition shown in Fig.

Specification of Letters Patent.

Application filed. April 16, 1910.

Patented Apr. 18, 1911. Serial No. 555,886.

is connected by the screw 16 in the arm 11 and by means of the screw 17in the blade 3. It will readily be observed that as the lever 12 isswung on the pin 13, the bars of the toggle lever are swung operatingthe blade 3 and as the point of contact of the cutting edges recedesfrom the pivot, the toggle lever approaches alinement and consequentlyincreases its power in proportion to the distance from the pivot of theblades to the point of contact of the cutting edges.

The link 18 is connected by a screw 19 with the lever 10, and by screw20 with the lever 12. It will be observed, therefore, that as the lever12 is swung to close the blades, the lever 10 and movable mounting 7 arealso moved. As the point of contact between the cutting edges recedesfrom the pivot, the screw 20 forming a' pivot pin between the link 18and lever 12 swings around the pivot pin 13 with the lever 12 so as toapproach alinement with the pivot 19, thus increasing the power of thelever 12 in its action upon the lever 10. In Fig. 3, it will be observedthat the pivot 20 is brought approximately to alinement with the pivots13 and 19. From this it will be seen that not only is the leveragethrough the toggle lever proportioned to the distance between the pointof contact between the cutting edges and the pivots of the blades, butthe mechanism for actuating the movable mounting also shifts itsleverage to vary as the distance between the point of contact betweenthe cutting edges of the blades and their pivots varies. In this way,with a uniform force on the lever 12 an approximately uniform cuttingaction along the entire length of the cutting edges of the blades iseffected. The link 15 has the extension 21. This extension engages theshank of the blade 1 as the shank of'the blade 3 is forced down, andbeing thus interposed between these shanks prevents'the spreading of thecutting edges of the blades. A

It will be noted that the cutting edges are given a slight longitudinalmovement relatively to each other due to the arc of movement of themovable mounting.

It will be noted that the link 15 has the extension 21 which, operatingagainst the handle end of the blade 1, tends to hold the cutting edgesat and 5 in engagement.

\ZVhat I claim as new is:

1. In a shear the combination with the shear blades; of a pivotalmounting for one of the blades; means for automatically shifting themounting relatively to the other blade as the blades are operated.

2. In a shear the combination with the shear blades; of a swingingmounting pivotally connected to each of the blades; and means forautomatically swinging the mounting as the blades are operated to changethe pivotal relation of the blades.

In a shear, the combination with the shear blades; of a swingingmounting pivotally connected to each of the blades; a lever extendingfrom the mounting; and means acting on the lever for swinging themounting to vary the relation between the blades.

4. In a shear, the combination with the shear blades; of a pivotalmounting for one of th e blades; and means for automatically shiftingthe mounting relatively to the other blade to move the cutting edge ofthe one blade relatively to the cutting edge of the I other blade.

5. In a shear the combination with the shear blades; of a pivotalmounting for one of the blades; means for automatically shifting themounting relatively to the other blade as the blades are operated tomove the blades transversely relatively to each other.

6. In a shear, the combination with the shear blades; of an actuatinglever mounted on one of said blades; means for communicating a movementof the lever to the other of said blades; a pivotal mounting for one ofthe blades; a movable support on the other of said blades; and aconnection between said actuating lever and said mounting forautomatically shifting the mounting as the blades are operated.

7. In a shear the combination with the blades; of an actuatinglever'mounted on one of said blades; means for communicating themovement of the lever to the other of said blades with an increasingleverage as the blades close a pivotal mounting for one of v the blades;a movable support on the other of said blades; and a connection betweenthe said actuating lever and mounting for automatically shifting themounting as the blades are operated.

8. In a shear the combination with the blades; of an actuating levermounted on one of said blades; means, for communicating the movement ofthe lever to the other of said blades; a pivotal mounting for one, ofsaid blades; a movable support on the other of said blades; and aconnection between the said blades and mounting to automatically shiftthe mounting transversely as the blades are operated with an increasingleverage as the blades are closed.

9. In a shear the combination with the blades; of an actuating levermounted on one of said blades; a bar connecting said lever and the otherof said blades forming: a toggle joint; a swinging mounting pivotallyconnected to the pivot of said blades; a V

mounting lever extending from said mounting; a link between saidmounting lever and actuating lever, the mounting being arrangedrelatively to the pivots to move the blades transversely toward eachother as the actuating lever actuates the blades through the togglelever-to close the blades.

10. In a shear the combination with the blades; of an actuating levermounted on one of said blades; means for communicating the movement ofthe lever to the other ofsaid blades, comprising an extension 20 forengaging the first blade, and holding. the ends of the blades againstlateral displacement.

11. In a shear the combination with the blades; of an actuating levermounted on one of said blades; a bar connection between said lever andthe other of said blades, forming a toggle joint; and anextensionon saidbar engaging the first of said blades preventing a lateral displacementof the cutting edges of said blades relatively to each other.

12. In a shear the combination witlrthe blades; of an actuating levermounted on one of said blades; a bar connecting said lever and the otherof said blades forming-a toggle joint; a swinging mounting pivotallyconnected to each of said blades; a mounting lever extending from saidmounting; a l nk between said mounting lever and actuating lever, themounting being arranged rela- HARRY M SWAN.

lVitnesses:

J. C. 'IHoMs, Roar. J. OSBORNE.

Copies of this patent may be obtained for five cents each, by addressingt he Gommissioner of Patents,

Washington, D. G.

